First appears in "The Temple" as an ivory carving with no name attributed to it.
The name "Gloon" seems to have appeared in a scenario in Cthulhu Now (G.W. Thomas's scenario "The City in the Sea"), and then in Malleus Monstrorum. (The word "gloon" seems to have first appeared in Bulwer-Lytton's 1871 novel Vril, or The Coming Race (fiction), allegedly a word from the language of the Vril-ya (underground civilization of the novel) and means "town".)
Gloon, "Corrupter of Flesh" and "Guardian of the Atlantean Temple", may appear to worshipers as a tall, beautiful, naked young man wearing a laurel wreath, but its true form is that of a wrinkled, slimy, slug-like horror. (Malleus Monstrorum)
Possessing a statuette or idol of Gloon and touching it with bare hands will curse full-blooded humans with strange nightmare visions of sunken Atlantis and Gloon's ruined temple, carved from solid rock in a valley where a river once ran before the continent was submerged, the temple lit from within by some strange luminescence, with the ghastly dancing forms of Gloon's Deep One worshipers silhouetted against the windows and doorways. ("The Temple")
The cult of Gloon may typically consist of Deep Ones and their human collaborators and hybrids, and worship of Gloon may appear side-by-side with worship of "Father" Dagon, "Mother" Hydra, and Cthulhu, with some details appearing in the Cthäat Aquadingen, The Pnakotic Fragments, and in other tomes associated with Atlantis and water demons and cults.
- "Our men searched him for souvenirs, and found in his coat pocket a very odd bit of ivory carved to represent a youth's head crowned with laurel.... I could not forget the youthful, beautiful head with its leafy crown, though I am not by nature an artist." - HPL "The Temple"
Rumors and Speculation
- Gloon may be a anthropomorphic, conventionalized representation of Dagon/Cthulhu carved by Atlantean artisans in a form less disconcerting to human worshipers of the Cthulhu cult, portraying Cthulhu and its Deep One priests as a beautiful male, human youth, to reassure those unfortunate human women chosen as "sea brides" for "Dagon", in much the same way that Gloon's female counterpart is conventionalized as a beautiful mermaid for the comfort of human men who are to marry sea-maidens of the Deep Ones.
- The Comte d'Erlette insisted in his infamous Cultes des Goules that Gloon was a "water elemental", and systematically traced relationships and conflicts between Gloon and other supposed "elemental spirits" in elaborate family trees that may contain at least as much fantasy as accurate historical information.